Rincón-Tuexi¹, Sergio Castro-Nava², José Alberto López-Santillán², Alfredo J Huerta³, Carlos Trejo-López⁴, Florencio Briones-Encinia

Phyton-International Journal of Experimental Botany, Vol.75, pp. 31-40, 2006, DOI:10.32604/phyton.2006.75.031

Abstract Effects of water and high temperature stresses, either separately or in combination, over biomass accumulation, grain yield and its direct components grain number per ear and individual grain weight], as well as harvest index were determined in four tropical maize populations. Results indicated that water stress do not significantly affect the studied variables, due to the absence of a severe water stress during flowering. This was the result of the fallen precipitation at this time. The most important factor in this study was high temperature, which significantly reduced all studied variables, except individual grain weight.… More >

Carolina Saint Pierre, Carlos Alberto Busso

Phyton-International Journal of Experimental Botany, Vol.75, pp. 21-30, 2006, DOI:10.32604/phyton.2006.75.021

Abstract This article has no abstract. More >

Galatro Andrea, Ivan Rousseau, Susana Puntarulo

Phyton-International Journal of Experimental Botany, Vol.75, pp. 7-20, 2006, DOI:10.32604/phyton.2006.75.007

Abstract Electron Paramagnetic Resonance (EPR) has been developed as a versatile field that uses different techniques sharing the common feature of resonant micro-wave radiation absorption by paramagnetic substances. Certain free radicals, such as ascorbyl radical (A•), show an stable spectrum, and can be directly detected by EPR at room temperature. Studies included in this work clearly show that this highly sensitive methodology can be successfully applied to biological systems. Exposure of plants to UV-B radiation was studied as a factor of oxidative stress in plants, and the effect on A^• steady state concentration was analyzed. A kinetic More >

C.P. Providakis¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 249-254, 2006, DOI:10.3970/sdhm.2006.002.249

Abstract This paper explores the concept of strain energy density rate in relation to the crack initiation in fracture analysis problems arising in creeping cracked structural components. The analysis of the components is performed by using the boundary element methodology in association with the employment of singular boundary elements for the modeling of the crack tip region. The deformation of the material is assumed to be described by an elastic power law creep model. The strain energy density rate theory is applied to determine the direction of the crack initiation for a center cracked plate in More >

J. Toribio ¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 239-248, 2006, DOI:10.3970/sdhm.2006.002.239

Abstract This paper reviews the fracture performance in air and aggressive environment (stress corrosion cracking) of eutectoid prestressing steel wires with different levels of cold drawing. In air environment, a micromechanical model of fracture is proposed to rationalize the results on the basis of the microstructure of the steels after drawing and the model of Miller & Smith of fracture of pearlitic microstructure by shear cracking of the cementite lamellae. In hydrogen assisted cracking (HAC), a microstructure-based model is proposed on the basis of the Miller & Smith model and the mechanism of hydrogen enhanced decohesion or, more More >

P.D. Shah¹, Ch. Song², C.L. Tan¹, X. Wang¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 225-238, 2006, DOI:10.3970/sdhm.2006.002.225

Abstract Numerical T-stress solutions in two dimensional anisotropic cracked bodies are very scarce in the literature. Schemes to evaluate this fracture parameter in anisotropy have been reported only fairly recently. Among them are those developed in conjunction with two different computational techniques, namely, the Boundary Element Method (BEM) and the Scaled Boundary Finite-Element Method (SBFEM). This paper provides a review of the respective schemes using these techniques and demonstrates their efficacy with three examples. These examples, which are of engineering importance, involve cracks lying in a homogeneous medium as well as at the interface between dissimilar media. More >

E.J. Sapountzakis¹, V.G. Mokos¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 207-224, 2006, DOI:10.3970/sdhm.2006.002.207

Abstract In this paper a boundary element method is developed for the second-order analysis of frames consisting of composite beams of arbitrary constant cross section, taking into account shear deformation effect. The composite beam consists of materials in contact, each of which can surround a finite number of inclusions. The materials have different elasticity and shear moduli with same Poisson's ratio and are firmly bonded together. Each beam is subjected in an arbitrarily concentrated or distributed variable axial loading, while the shear loading is applied at the shear center of the cross section, avoiding in this… More >

H. Hadavinia¹, K. Gordnian¹, J. Karwatzki¹, A. Aboutorabi¹

Structural Durability & Health Monitoring, Vol.2, No.4, pp. 197-206, 2006, DOI:10.3970/sdhm.2006.002.197

Abstract The cylindrical bending of thick laminated sandwich plates under static loading is studied based on the first order shear deformation theory (FSDT). FSDT generally requires a shear correction factor (SCF) to account for the deflection owing to the transverse shear. In this paper the SCF is derived using energy equivalence method. It is shown that depending on the mechanical and geometrical properties of the layers, the contribution of the transverse shear stress to the maximum deflection of the plate is variable and in some cases account for up to around 88% of the total deflection. More >

R. Citarella¹, A. Apicella²

Structural Durability & Health Monitoring, Vol.2, No.3, pp. 183-196, 2006, DOI:10.3970/sdhm.2006.002.183

Abstract This paper presents an overview of the achievements of a research and development project sponsored by the European Commission in the general area of Key Actions and New Perspectives in Aeronautics. The project was coordinated by Alenia and involved partners from major European Aircraft and Helicopter manufactures as well as research institutions and universities. The project was in support of EU policies on energy and environment, in addition to those on transport, economic and social cohesion, industry and, of course, research and technology.
The overall objective of Advanced Design concepts and Maintenance by Integrated risk Evaluation… More >

G. Davì¹, A. Milazzo¹

Structural Durability & Health Monitoring, Vol.2, No.3, pp. 177-182, 2006, DOI:10.3970/sdhm.2006.002.177

Abstract An alternative single domain boundary element formulation and its numerical implementation are presented for the analysis of two-dimensional cracked bodies. The problem is formulated employing the classical displacement boundary integral representation and a novel integral equation based on the stress or Airy's function. This integral equation written on the crack provides the relations needed to determine the problem solution in the framework of linear elastic fracture mechanics. Results are presented for typical problems in terms of stress intensity factors and they show the accuracy and efficiency of the approach. More >